話さなく is 話さない(not speak) adverbialised ＋ なった, the past form of なる(to become)
So, the translation "Hanna, why is it you’ve never talked to Paul?" I think is a little off. I would equate it to closer to something like "Hanna, why have you stopped talking to Paul?"
Here, わけ can be interpreted as reason or cause. As cirno said, with 話す, it then means 'state one's reasons,' this can be read as 'If you state your reasons for me'
The second half I believe has a typo with a second あ added, and should be '何か助けてあげられるかもしれないよ'
何か(something) + 助けて(to help) + あげられる(potential form of あげる, to give) + かもしれない(possibly, may be)
何か助ける would be something like 'give some kind of help.' Conjugating to て-form and adding あげる means you are giving the action of helping, in this case to the listener Hanna, so 'do the favor of giving some kind of help to you(Hanna)'
Add in potential form and かもしれない, you get 'possibly I would be able to do you the favor of giving some kind of help.'
Putting the whole sentence together and making it sound a little natural in English: "If you tell me why, I might be able to help you."